In general, brassieres' metal hooks are seamed on the belts at two sides of the cups. By the metal hooks, the two belts can be connected together. Thus, the brassiere can be worn on a woman. However, in washing, by hand, the metal hooks are possibly hooked on the user's hand. In general, the metal hook is made of iron material and then is processed by plating. The plated layer easily is removed due to washing. Once the plating layer is removed, the iron metal will generate rust so as to stain the clothes. Moreover, plating will generate a large amount of industrial waste water. Recently, the sense of environment pollution is more and more of a concern such kind of buckle is not acceptable.
Therefore, current brassieres employ buckles made of plastic material, as shown in FIG. 4. In this kind of buckle, the buckle sets are connected to the left and right belts of the cups of the brassiere. The distal end thereof has a hook a1 and a plate a2 which are integrally formed and then are clamped to a belt b. Thus, the hook and plate have a large volume, i.e. a large thickness. From the figure, it is shown that if a force is applied, the buckle sets a will be tightly buckled. However, the force is very possible to generate twisting force so that the hooks are possibly released. The reason of the twisting force is that if a force is applied, one side of the buckle a will be twisted so that the hook is possibly released. Therefore, such a structure is not an ideal structure.
Besides, as shown in FIG. 5, the buckle set is formed by a male buckle c and a female buckle d. The male buckle c has a protrusion c1, and the edge of the protrusion c1 is installed with a lip portion c11. An oblong joint hole d1 is installed in the female buckle d. The protrusion c1 of the female buckle c can be pressed into the joint hole d1 of the male buckle d. Since the joint hole d1 of the female buckle d has an oblong shape, even the positioning of the male buckle c and the female buckle d are not accurate. The protrusion c1 of the male buckle c can still be easily pressed into the joint hole d1 of the female buckle d so that the male buckle c may press into the female buckle d. Such kind of buckling may be embodied in various objects. If it is embodied in a brassiere, the lip portion c11 atop the protrusion c1 of the male buckle c projects through the joint hole d1 of the female buckle so that it can be connected to the two belts at the rear side of the brassiere. But the lip portion c1 on the male buckle c projects through the joint hole d1 of the female buckle d by the elasticity of the material of the lip portion itself. If the lateral force is too large, the male buckle c and female buckle d are easily released. Therefore, this design is not ideal.
Thus, as described above, in one prior art embodiment, the metal hook is connected to the belt of a brassiere, and in washing, the plated layer easily falls off due to washing. Once the plating layer is removed, the iron metal will rust so as to stain the clothes. The structure shown in FIG. 4, has a large volume, i.e. a large thickness. If a force is applied, the buckle sets a will tightly buckle. However, the force is very possible to generate twisting force so that the hooks are possibly released. For the structure shown in FIG. 5, the lip portion c1 on the male buckle c projects through the joint hole d1 of the female buckle d by the elasticity of the material of the lip portion itself. If the lateral force is too large, the male buckle c and female buckle d are easily released. Thus, the abovesaid prior art structures not ideal designs.